The field of the invention generally relates to coin operated devices, and more particularly relates to apparatus and methods for discriminating and collecting coins.
As is well known, there are a variety of coin operated devices such as laundromat equipment, vending machines, toll booths, and public telephones. Generally, such devices identify a deposited coin or token by detecting coin characteristics or parameters, and then comparing them to corresponding standards that are known for acceptable coins of different denominations. For example, some of these parameters are coin diameter, thickness, ferrous content, and weight.
Some of the more successful coin discrimination schemes employ a combination of parameters such as coin diameter discrimination combined with sensing the metal characteristics of the coin. For example, a typical prior art coin diameter discriminating device may employ some sensor to detect the passing of a rolling coin. In particular, one or more optical sensors maybe arranged along a ramp along which the coin rolls. The diameter is then determined by measuring the time required for the coin to pass the sensors. When only one sensor is used, the device may discriminate the diameter of a coin on the basis of the time during which light from an emitter is shielded from a photodetector by the coin passing therebetween. It is apparent that when suitably arranged, a large coin will break the light beam for a longer period of time than a small coin. Thus, the measured time is related to the size or diameter of the coin. The measured time is then compared to ranges of times derived from a data bank of measurements made on a variety of acceptable coins. A metal content measurement can be made such as described in U.S. Pat. No. 3,966,034, and in like manner the measured data can be compared to corresponding ranges for acceptable coins. If a received coin falls in all of the ranges for a particular coin denomination, the coin maybe accepted as being a genuine coin of that denomination. Under such condition, an accumulator is generally incremented, and the coin is routed to a coin collection box rather than to a coin return slot.
There are a number of disadvantages with prior art coin discriminating and collecting devices. First, coin entry slots are generally left open so additional coins may be inserted while evaluation of a previously inserted coin is still being conducted. Such action may interfere with the present evaluation and/or the coins may become jammed. Further, once jammed, there generally is no way to correct the anomaly until a service technician opens the mechanism. Another problem is that coin discrimination and collection devices are often susceptible to tampering or being cheated. For example, one technique is to insert implements into the coin slot. In another technique called stringing, the coin is retrieved using a string or wire after the coin's value has been accumulated.